Field of the Invention
The present invention relates to a power amplification module.
Background Art
In a radio communication system, such as GSM® (Global System for Mobile Communications) or EDGE (Enhanced Data Rates for GSM Evolution), during a burst operation to continuously send data from a communication terminal, there is a demand for changing power of a transmission signal (burst signal) according to the waveform characteristic defined by the communication standard.
A specific example will be described. FIG. 10 is a diagram illustrating an example of a waveform characteristic defined for a burst operation. As illustrated in FIG. 10, it is desirable to control the level of the transmission signal such that the signal level of the transmission signal falls between an upper limit (LUL) and a lower limit (LDL). As a method of controlling the level of the transmission signal, two kinds of a method of controlling input power with a constant gain of the power amplification module and a method of controlling the gain of the power amplification module with constant input power are known.